Short range wireless communication systems using the Bluetooth (registered trademark) protocol have been developed and put into practical use. In such a short range wireless communication system, electronics devices, such as a personal computer, a printer, a digital camera, or the like, are connected without using a cable. Recently, headsets using the Bluetooth protocol have been also developed. Wireless headsets eliminate the need of a cable that connects with an audio source. Therefore, in case that a user listens to music, etc, it is an advantage that the user is relieved of the inconvenience of tangled cables, or the like.